<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .div{
            display: flex;
            width: 60%;
            height: 600px;
            background-color: pink;
            flex-wrap: wrap;
            /* 因为换行了，所有我们侧轴控制子元素的对齐方式用 align-content 
              子项多行用这个align-content 
               子项单行用align-items*/

            /* 垂直居中 */
            align-content: center;
            /* 靠上对齐 */
            /* align-content: flex-start; */
            /* 平分空间 */
            /* align-content: space-around; */
            /* 两边贴边 */
            /* align-content: space-between; */
        }
        .div div{
            width: 200px;
            height: 100px;
            background-color: aqua;
        }
    </style>
</head>
<body>
    <div class="div">
        <div>1</div>
        <div>2</div>
        <div>3</div>
        <div>4</div>
        <div>5</div>
    </div>
</body>
</html>